Some background on this comic:

Transcript of relevant bits:

In my first year or so of drawing The Far Side, I was scared to death of making mistakes in the artwork. Incredibly, I had never heard of a product called “White Out” (for covering up mistakes) and the smallest screw-up meant starting over. So, as I’ve indicated under each of these cartoons, I sometimes left things out

This is interesting. I have no idea where this guy’s legs are